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Diff front mounting bushes is this right?


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Hi all

Me again ..... well I have started over again

stripped the body off and started to sort out a leak from the diff.

however I have a question. some time ago I bought a set of polybushes for the coupe (black ones) I have done the front with no problems.

But at the rear the front diff mounting bushes seen to be very big compared to the rubber ones that I have just taken off.


I know that the rubber ones will squash down somewhat when done up and over time with uses, but they were new Stanpart units when I put them in some 20 odd years ago and the car was never finished so had never driven. And there was no slaking on the fittings to indicate wear.

If I put the new polybushes in as they are, would that not push the angel of the prop down (or up?) as the diff pivots on the rear mountings. So my question is should I take a bit off the new polybushes or not. And if so how much

my thinking is if the rubber ones are made the squash down to give the tension, then that’s ok for the rubber ones , but I can not see that the polybush ones will squash down to give the same tension ant the same depth, if you see what I me.

Any help would be very mush appreciated.

when needs must and a swing is all you have!


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The mounting bolts for the diff front mount have a shoulder, so cannot be tightened further than the end of the threads. New rubber bushes are quite big but will compress once the nut has been torqued down to the correct value; they can't be compressed any further. You might be tempted to leave them looser than they should but this will only accelerate wear and allow flex when moving. 

Don't be tempted to trim the polybushes, they're made to the correct size and will compress to some amount, but not as far as the rubber ones do. Torque a new nyloc up to the required tension - which I THINK(!) is 26-28 lb ft, but cannot find confirmation of that anywhere at present, can anyone confirm? - and that'll be as far as you need to compress them. They won't flex as much as the rubber ones so less compression will not mean more movement. It won't affect the prop angle, or certainly not any more than the car is designed for.

I like the swing - need a push?

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Thank you Colin (and Pete) for the clarification and the torque setting. I now see what you mean about the front mount have a shoulder.

Just needed to get it strait in my head.


Had to balance the body on the swing with a heavy tool box on the front.. 😊

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  • 6 months later...
23 hours ago, Neil Clark said:

I got stuck on these bushes.  They just would not sit down in the "cups" and I couldn't get them settled enough to tighten the nuts.  Along comes the wife and says "why don't you use WD40? to make them slide in".  I don't know why I hadn't but she was right.

I have various liquids for lubrication in small containers in the garage for just that sort of thing.  There’s silicone lube, Vaseline, fiery liquid, soap, KY, and a wd40 type of thing. You never know when you are going to need the right sort of lubrication. 😲

My Dad always used a bit of soap on woodscrews to help them in. that was before the days of impact drivers😊

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